The present invention relates to a photo sensor array and a reader, and more particularly to a photo sensor array and a reader which require neither an optical unit or a selfoc lens nor etching step, and which can improve the yield of products.
Hitherto, singlecrystalline sensors such as CCD having a structure in which plural MOS sensors are linerly arranged, or contact-type sensors using amorphous semiconductor or CdS have been used as reading sensors in telecopier equipments and the like. However, in singlecrystalline sensors, the size the of photo-receiving portion is small, so that an optical device including, for example, a lens for converging reflected light from a manuscript is required to be provided between the manuscript to be read and the sensor. In that case, an appropriate optical path is required so that the device inevitably becomes large. For contact-type sensors, the device can be miniaturized since an optical path is not required due to the use of a selfoc lens. However, the contact-type sensor has a drawback because a selfoc lens is required to be provided on the photo sensor array.
Recently there has been proposed a perfect-contact-type sensor using amorphous semiconductor wherein a part of the semiconductor is removed (patterned) by an etching process and the light is designed to enter into the etched portion. This type of sensor has, however, a drawback because of pinholes generated in the semiconductor layer during the etching process which lowers the yield of the products.
The present invention was made to solve the above-mentioned drawbacks of the conventional photo sensor arrays, and it is an object of the present invention to provide a photo sensor array and a reader which do not require an optical unit or a selfoc optical unit, and which can improve the yield of products since an etching treatment or the like, is not required for the semiconductor layer.